Moving stairway



J. DUNLOP MOVING sTAIRwAY Feb. 22, 193s.

Filed June 26, 1937 w mw m m R WNW n Patented Feb. 22, 1938 UNITED STATES PATENT QFFIQE MOVING STAIRWAY Application June 26, 1937, Serial N0. 150,493

6 Claims.

My invention relates to moving stairways and more particularly to devices for ensuring the safe operation of such stairways.

In following the operation of moving stairways I have found that there is a denite risk involved in the operation of the stairway as it approaches the cornbplate because of the inability of immediately stopping the stairway when articles get caught along the sides of the steps as they approach the combplate, or because something has caused a step to rise as it is about to pass under the combplate. When an accident results from one of these causes, it occasions considerable damage which might be avoided if the stairways were stopped immediately upon their rst faulty action.

Therefore, it is an object of my invention to provide a safety means which will cause a stairway to stop its operation immediately when anything becomes jammed between the combplate and the steps, particularly at the ends of the steps, and also when anything causes a step, as it approaches its combplate, to rise to such an extent that it will not pass under the combplate without crushing against it.

Another object is to provide a moving stairway safety device which shall be simple and economical to construct, operate and maintain in operation.

For a better understanding of the invention, reference may be had to the accompanying drawing, in which:

Figure 1 is a View, partly in side elevation and partly in section, of a portion of the upper landing of a moving stairway provided with a safety device constructed in accordance with my invention;

Fig. 2 is a top plan view of a large portion of the moving stairway upper landing shown in Fig. 1;

Fig. 3 is a view in cross section of a portion of the safety device and step tread shown in Figs. 1 and 2, and

Fig. 4 is a modification of the safety device i1- lustrated in Fig. 1.

Referring more particularly to the drawing, I have illustrated the upper landing portion of a moving stairway as supported upon a suitable framework, a small portion of which is shown as a pair of I-beams 1 and 2, a vertical standard 3 and a strut li. A track rail 5 is supported upon the standard 3 by means of suitable brackets 6 and secured to the strut 4 by rivets 1. A second track rail 9 is disposed about the first track rail 5 and is maintained in position by the standard 3.

A guard rail I is mounted upon the standard 3 above the track rail 9 in position to cooperate therewith. The track rails 5 and 9 comprise the upper track for the moving stairway. A pair of lower track rails Il and I2 are attached to the vertical standard 3 by suitable brackets I3 to provide the lower track.

As shown, the moving stairway comprises an endless series of movable steps l5 which are disposed to move along the track rails 5 and S in accordance with the speed at which the stairway is to be operated. Each of the steps l5 comprises a step tread ll disposed upon a frame comprising a pair of horizontal bars or joists I3 and i3 supported by suitable risers 20 and 2l. The lower ends of the risers are suitably connected by end bars 22 (only one of which is shown) to constitute a frame for the step tread.

Each of the step treads l1 is provided with a plurality of suitable parallel cleats 23 disposed in alinement with the stairway and a sufficient distance apart to provide a plurality of grooves 24. The cleats Should be of such dimensions and spaced such distances apart as to provide suitable supports for the feet of the passengers without permitting the heels of the passengers shoes to enter the grooves.

The front portion of the step indicated by the riser 2| is supported by a pair of leading wheels 25 while the rear portion of the step is supported by a pair of trailing wheels 26. With the step in its upper or stairway position, the leading wheels 25 travel on the track rail 9 and the trailing wheels 26 travel on the track rails 5.

The leading wheels 25 are mounted upon an 35 axle 21 which extends through a geared chain 28 at each side of the step. Each of the gear chains 28 is provided with a plurality of rollers 29 by means of which it is supported upon and driven by a suitable sprocket wheel 30. The sprocket wheels are firmly mounted upon and driven by a suitable driving shaft 32. The rotation of the sprocket wheels causes the gear chains 28 to move in accordance with the direction of operation of the sprocket wheels thereby carrying the endless series of steps l5 around inl their operative position.

Inasmuch as the gear chains on the sprocket wheels support the leading wheels, they do not need to be supported by track rails as they follow the gear chains around the sprocket wheels at the landings. However, the trailer wheels ll are not connected directly to the gear chains. Therefore, track rail 5 is continued by a curved section 34 to extend around the axis of the sprocket wheels. 55

A curved guard rail is disposed to guide the trailer wheels 26 along the curved track section An electric motor 38 is provided for drivingthe sprocket wheels, through a countershaft 39, a reduction gearing 40and a driving chain 4|. An electro-magnetically controlled spring-applied brake 42' is disposed on Vthe motor shaft V32 Vfor stopping the stairway and preventing its operation when the motor 38 is deenergized.

Although any suitable control circuit may be Y the cleats 23 of each step as it moves through its .uppermost position and causes the feet of the passengers to be transferred from orto the steps as the starway operates in the up orV the down direction. The combplate may be mounted upon the structural beams I and 2 in any suitable In order to stop the operation of the stairway when any obstruction on the tread Yof the step at the side of the stairway is likely to be jammed against the teeth of the combplate or when a step Vrises out of its normal running'position to such 'I an extent, as it approaches the combplate, that continued movement of the step will cause it toV crash into Ythe comb teeth, I have provided a Y pair of Vfeeler fingers and 5I for determining whether or not the steps are free of obstructions and are in alinement with the comb teeth.

T'nenger 5i) is mounted on oneV end of the combplate by a pivot52 with its rear portion 53 extending under a shoulder 54 formed on the combplate. The front end of the finger is pro- -K vided with a feeler portion 55V which extends Vseveral inches beyond the front edge of the comb' teeth 46 and alongside the point where the edges of the steps and the balustrade 56 meet.V The height of the fingerr is about the same as that of the teeth 46 and, inasmuch as the rear portion of the yfinger extends under the shoulder 54 of the combplate, the feeler portion of Ythe finger can be stepped upon by the passengers without c moving it in any way. .The rear portion of the f nger is connected to a AswitchV 51 having a pair of contact members 58 biased to a closed position by a spring 59. 'Ihe switch may be mounted in any suitable manner, as upon the I-beam l, and its contact members are so connected in the control circuit 60 Vfor the stairwayY motor andV brake-that the stairway'will stop when the switch opens. Y Y

Y With this construction, if the step risesout of its normal running position as it approaches YYthe combplate, orif it Yh'asan obstruction say like thesole of Va boys shoe caught in it, it will Vcause the feeler portion of. the finger to riser and thereby move the rear portion of the finger downwardly, thus opening the switch 51, break- Y ing the Vcircuit 60, deenergizing the motor 38 and applying the brake^42 to stop theY stairway.' Inasmu'ch as stairways; of this character are provided with powerful brakes and theireon- Atrol systems are rapidl in operation the use of i VtheV feeler nger 50 will causev the stairway to be stopped immediately before the step reaches the point of the comb teeth when the step is jammed or out of position and therebyY prevent damage to the stairway.

The finger 5| is Vmounted in the opposite end of the combplate in the same manner as that described for the finger 50. The fingers arel 1ocated at each side of the steps to ensure as great a degree of safety as possible. Y Y,

It will be obvious that the feeler finger 5.0 or 5|`may be mounted in any other manner in any other position where it will bel operated to openY its switch by the steps rising out of their normal running position. yFor instance', in Fig. 4, the finger 5 la is constructed witha vertical shaft 62 slidably Ydisposed in a block 63 mounted on Va portion of the balustrade 56a. A switch 58u having its contact members connected in the control circuit 60 is disposed at the upper end of the shaft B2. With this arrangement, if a step, raised slightly out of its normal running position, engages the finger Sla, it will move the shaft 62 and thereby open the switch 56a thus interrupting the control circuit-60 to effect the stopping of the motor and the stairway.

By reason of the foregoing description, it will be seen that'I have provided a simpleV and inexpensive means for enhancing the safe operation of movingstairways and that itis :economical to construct, operate and maintain` in operation.

. Although I have illustrated and described only Y one specific embodiment of my invention, itis to be understood that many changes therein and modifications thereof ymay be lmade without departing from the spirit'and scope thereof.

I claim as my` invention: Y y Y '1. In a moving stairway provided with steps having treads, the'k combination with a motiveY means for driving the steps and .a combplate disposed at one end of thestairway, of a finger having a feeler portion, means for mounting the finger with its feeler portion normally extending over a portion of the tread of a step away from the combplate, whereby it will be moved upwardly out of its normal'v position by the step When the step is raised out ofits normal running position, and means responsive to vmovement of the finger outY of its normal position for` rendering the'motive meansineffective and Ystopping the operation of the steps. y

2. In a moving stairway having steps provided with treads, the combination with a motor means for driving the steps and a combplate vdisposed at one end of the' stairway, of a feeler finger, meansV for mounting the feeler finger adjacent to the combplate with the feeler portion of the finger extending beyond the teeth of the vcombplate into a normal position close to the tread of the step approaching thercombplate and in position to be engaged by and moved out of its normal position by a step raised out of its normal running position in approaching the combplate Y' or by an obstruction on the step, and means responsive to the movement of thefeelerV finger outr of its normal position for Vrendering the motor means ineffective and for stopping the stairway steps. K' Y f 3. In a moving stairway having steps provided with grooves in theirY treads, the combination Vof the steps as they pass to the combplate, of a m With means for driving said steps, a frame disfeeler iinger mounted on the combplate and extending in front of the teeth of the combplate and out of line with the normal line of approach of the steps to the combplate but in position to be engaged and moved by a step when that step rises above its normal running position in approaching the combplate, and a switch responsive to movementof the feeler finger out of its normal position for rendering said means ineffective and stopping the stairway.

4. A moving stairway having steps provided with grooves in their treads, means for driving the steps, a combplate disposed at one end of the stairway with its teeth disposed to enter the grooves in the treads of the steps as they pass under the combplate, a pair of feeler fingers, means for pivotally mounting one of the fingers at each side of the combplate in position to extend beyond the teeth of the combplate and to enter cooperating grooves in the treads of the steps as they approach the combplate but in position to be engaged and moved upwardly out of normal position by a step raised above its normal running position in approaching the combplate or by an article lodged on that portion of the step adjacent the nger, and switch means responsive to movement of either finger out of its normal position for rendering the driving means ineffective and stop-ping the stairway steps.

5. In a moving stairway having steps provided with grooved treads, motive means for driving the steps, a combplate mounted at one end of the stairway with its teeth disposed to enter cooperating grooves in the step treads as they pass under the combplate and provided with shoulders, a pair of ieeler ngers, means for pivotally mounting a finger upon each end of the combplate with its one end extending under a shoulder on the combplate and its other end extending forwardly beyond the teeth of the combplate in line with cooperating grooves in the steps whereby a step raised out of its normal running position will tilt the finger, and means responsive to 15a tilting action of either of the ngers for rendering the motor ineffective and stopping movement of the steps.

6. In a moving stairway .having an endless series of steps, a combplate disposed at 'one end of the stairway, a motor for driving the steps under the combplate, a control circuit for the motor, a normally closed switch in the circuit, a feeler finger, means for pivotally mounting the finger adjacent to the combplate with the feeler portion of the iinger extending beyond the teeth of the combplate into a normal position close to the tread of the step approaching the combplate and in position to be engaged by and moved out of its normal position by a step raised out of its normal running position in approaching the combplate or by an obstruction on the step, and means connecting the rear portion of the finger to the switch whereby operation of the finger out of its normal position will open the switch to eiTect deenergization of the motor and stop the stairway.

JAMES DUNLOP. 

